Rotary fan



G. B. ALLISON.

ROTARY FAN.

APPLICATION FILED DEC. 10, 1911. r

1,356,508. Paterited 001;. 26, 1920.

UNITED STATES PATENT OFFICE.

ROTARY FAN.

Specification of Letters Patent.

Patented Oct. 26, 1920.

Application filed December 10, 1917. Serial No. 206,398.

T 0 all whom it may concern Be it known that I, Gnoncn B. ALLIsoN, a citizen of the United States, residing at the city of Los Angeles, State of California, have invented new and useful Improvements in Rotary Fans, of which the following is a specification.

It is the object of my invention to produce a rotary fanof simple construction and great efficiency. 7

In the drawings forming a part of this application Figure 1 is a frontelevation of my improved fan.

Fig. 2 is a side elevation of what I term a two unit fan with parts in section and parts in elevation.

Fig. 3 is a plan in projection of the fan blades and hub, the fan shell being removed for clearness of illustration.

Referring to the drawings 5 is the easing or outer shell of my fan which is tubular in general outline. To the central portion thereof is secured an outlet or inlet tube 6 of smaller dimensions than the shell. To the ends of the outer shell are secured bearing arms 7 and 8 in which is revolubly mounted fan shaft 9 which carries on the end thereof pulley 10 to which power is applied to rotate the shaft. To shaft 9 at the ends of shell 5, if of double unit construction, are secured rotary fans composed of hubs 11 and blades 12. As shown diagrant matically in Fig. 3 the ends of the blades project at an angle to the plane of the revolution of the fan and the central portions travel in the plane of the revolution of the fan,, but in a two unit fan the angles of the fan blades at one end are the reverse of the angle at the other end. An outer shell 14c is secured to the outer edges of the fan blades.

When the fan is constructed as a double unit fan the shell is divided by a Y-shaped partition 13 the upper portions of which are curved as shown in Fig. 2. This partition deflects the air drawn into the shell into the outlet tube from which it passes to the place of use when the fan is used to drive air into a mine or other place of use. By reversing the direction of travel of the fan blades, the fan is equally powerful in sucking air out of a mine or other places from which it is desired to remove the air. 7

From the foregoing description it will be seen that a two unit fan can be constructed rotation as I prefer that angle for high speed, but the angle can be varied to suit the work to be done. I have also shown the central portions of the fan blades in the plane of rotation but if desired the blades could be straight but on an angle to the plane of rotation. By placing a shell on the outer ends of the fan blades the friction of the air on the outer shell is eliminated and it takes less power to rotate the fan. This shell is substantially as wide as the blades and braces the ends thereof and connects them together so that the outer ends at all points travel at the same rate of speed and without vibration.

Having described my invention, I claim:

1. A rotary fan comprising an outer shell; bearing arms secured to said shell; a shaft mounted in the bearing arms and shell; and a fan having a large central hub mounted on said shaft, the blades of said fan being secured to the hub and having the ends set angularly to the plane of revolution and the central portion set in the plane of revolution of the blades and a shell secured to the outer ends of the blades and revoluble therewith.

2. A rotary fan comprising a tubular shell; bearing arms secured to said shell at the ends thereof; a shaft mounted in said arms; fans having large hubs secured to said shaft adjacent to said arms, said fans having blades whose ends project at an angle to the plane of their revolution and the central portions lie in the plane of their revolution, the angles at one end being reversed as to those of the other end; an outlet tube secured to said shell, and a Y-shaped partition in said shell, said partition terminating centrally of said outlet tube.

In witness that I claim the foregoing I have hereunto subscribed my name this 3rd day of December, 1917.

GEO. B. ALLISON. 

